Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology (TU Delft), van der Maasweg 9, 2629 HZ Delft, the Netherlands; Faculty of Mechanical Engineering, University of Campinas (UNICAMP), R. Mendeleyev, 200, Cidade Universitária, Campinas 13083-860, Brazil.
Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology (TU Delft), van der Maasweg 9, 2629 HZ Delft, the Netherlands; Faculty of Chemical Engineering, University of Campinas (UNICAMP), Av. Albert Einstein, 500, Cidade Universitária, Campinas 13083-852, Brazil.
Sci Total Environ. 2020 Apr 20;714:136696. doi: 10.1016/j.scitotenv.2020.136696. Epub 2020 Jan 15.
The use of renewable jet fuels (RJFs) is an option for meeting the greenhouse gases (GHG) reduction targets of the aviation sector. Therefore, most of the studies have focused on climate change indicators, but other environmental impacts have been disregarded. In this paper, an attributional life cycle assessment is performed for ten RJF pathways in Brazil, considering the environmental trade-offs between climate change and seven other categories, i.e., fossil depletion, terrestrial acidification, eutrophication, human and environmental toxicity, and air quality-related categories, such as particulate matter and photochemical oxidant formation. The scope includes sugarcane and soybean for first-generation (1G) pathways and residual materials (wood and sugarcane residues, beef tallow, and used cooking oil-UCO) for second-generation (2G) pathways. Three certified technologies to produce RJF are considered: hydroprocessed esters and fatty acids (HEFA), alcohol-to-jet (ATJ), and Fischer-Tropsch (FT). Assuming the residual feedstocks as wastes or by-products, the 2G pathways are evaluated by two different approaches, in which the biomass sourcing processes are either accounted for or not. Results show that 1G pathways lead to significant GHG reductions compared to fossil kerosene from 55% (soybean/HEFA) to 65% (sugarcane/ATJ). However, the sugarcane-based pathway generated three-fold higher values than fossil kerosene for terrestrial acidification and air quality impacts, and seven-fold for eutrophication. In turn, soybean/HEFA caused five-fold higher levels of human toxicity. For 2G pathways, when the residual feedstock is assumed to be waste, the potential GHG emission reduction is over 74% with no relevant trade-offs. On the other hand, if the residual feedstocks are assumed as valuable by-products, tallow/HEFA becomes the worst option and pathways from sugarcane residues, even providing a GHG reduction of 67% to 94%, are related to higher impacts than soybean/HEFA for terrestrial acidification and air quality. FT pathways represent the lowest impacts for all categories within both approaches, followed by UCO/HEFA.
可再生喷气燃料 (RJF) 的使用是实现航空部门温室气体 (GHG) 减排目标的一种选择。因此，大多数研究都集中在气候变化指标上，但其他环境影响却被忽视了。在本文中，对巴西的十种 RJF 途径进行了归因生命周期评估，考虑了气候变化与其他七个类别（化石燃料枯竭、陆地酸化、富营养化、人类和环境毒性以及与空气质量相关的类别，如颗粒物和光化学氧化剂形成）之间的环境权衡。范围包括甘蔗和大豆的第一代 (1G) 途径和剩余材料（木材和甘蔗残渣、牛脂和用过的食用油-UCO）的第二代 (2G) 途径。考虑了三种生产 RJF 的经认证技术：加氢处理酯和脂肪酸 (HEFA)、酒精制喷气燃料 (ATJ) 和费托合成 (FT)。假设剩余原料为废物或副产品，2G 途径通过两种不同的方法进行评估，其中生物质采购过程要么被考虑，要么不被考虑。结果表明，与化石煤油相比，1G 途径导致 GHG 减排显著，从 55%（大豆/HEFA）到 65%（甘蔗/ATJ）。然而，基于甘蔗的途径在陆地酸化和空气质量影响方面比化石煤油高出三倍，在富营养化方面高出七倍。反过来，大豆/HEFA 导致人类毒性高出五倍。对于 2G 途径，如果假设剩余原料是废物，潜在的 GHG 减排将超过 74%，没有相关的权衡。另一方面，如果假设剩余原料是有价值的副产品，那么牛脂/HEFA 将成为最糟糕的选择，即使提供了 67%到 94%的 GHG 减排，来自甘蔗残渣的途径也与陆地酸化和空气质量相比，对大豆/HEFA 的影响更大。在这两种方法中，FT 途径在所有类别中都代表了最低的影响，其次是 UCO/HEFA。
